Interpretation of IPCC SR1.5 on cryosphere change and its impacts
Bo SU1,Xue-Jie GAO2,Cun-De XIAO1()
1 State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China 2 Climate Change Research Center, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
The cryosphere is highly sensitive to climate change among the five major spheres of climate system. Past decades, with the anthropogenic climate warming, has seen an accelerated retreat of the global cryosphere (including mountain glacier, frozen soil, snow cover and sea ice, etc.), which has also seriously affected global climate system and regional water resources, eco-environment, socio-economic development and human well-being. The IPCC Special Report on Global Warming of 1.5℃ (SR1.5) was issued in October 2018, it systematically presented basic scientific understanding of 1.5℃ global warming above pre-industrial levels and related global greenhouse gas emission pathways in the context of sustainable development and poverty eradication. In the cryosphere and related aspects, SR1.5 mainly projected some cryospheric changes (mainly sea ice, permafrost) and their impacts on the atmosphere, hydrosphere, biosphere, lithosphere and anthroposphere at a global average warming of 1.5℃ and higher levels of warming. It also focused on many climate change hotspots and tipping points under different global temperature goals, most of which are related to the cryosphere. As the temperature continues to rise, the risks to the cryosphere and its associated hotspots and tipping points will continue to increase. Limiting global warming to 1.5℃ compared to 2℃ or higher level is projected to lower the risks. However, frankly, SR1.5 has not given deep attention to the change and its impacts. In the future, it is necessary to deepen the research on the changes of the cryosphere and its related impacts and adaptation under different climatic scenarios, especially with the global 1.5℃ and 2℃ temperature goals and tipping points, thereby to explore a more sustainable and resilient pathway in the cryosphere affected regions.
Xiao C D, Su B, Wang X M , et al. Cascading risks to the deterioration in cryospheric functions and services[J]. Chinese Science Bulletin, 2019. DOI: 10.1360/N972018-01314 (in Chinese)